Help, I'm really bad now ;_:

So I haven't played actively since before September, with School + Work + a social life I'll find very few days that I can log in and play multiple games in a row now. Seeing a show today was Worlds Finals I asked the day off from work and went to a viewing party, I proceeded to go home and play some matches. Here are my scores: 1/8/7 3/11/5 4/8/6 In both of the Lee Sin games I tried to do what any other Lee SIn players do and go aggresive early, unfortunately in both games this ended with me dying very early on and multiple futile attempts at coming back into the game, I kept my score around 0/1-0/2 most of the time but once it was mid-late gam when we had to start grouping up I just started dying and dying and dying accomplishing nothing, My mechanics felt horrible, My Q's missed, my ult's would either be perfect or they would be completely off, It felt like my ward-hopping was extremely slow, and my reaction time was nowhere near what it used to be. With the Kha'Zix game I was DC'd for 5 minutes of the beginning part of the game cause of a CLient Bug, I was able to catch up to Rengar in CS because his ganks were constantly failing and I just kept farming, Eventually I caught up to his CS, and even passed him in levels. Once again when it got to mid-late game, I kept getting picked off, I kept on trying to farm and would find myself being ganged up on suddenly, I couldn't farm cause the enemies and allies took my farm, and I had extremely poor decision making and mechanics. The time that I wasn't playing the game frequently couldn't of affected me this hard could it? I was extremely active before around patch 5.16, but since around the time the juggernauts were released my game time lowered by a huge % and I couldn't play, My friends told me about how unfair they all were, the reworked fiora, and because of all the perma-bans I never even get to see those champions in action. Is there anyway to help me remember my decision making or bring back my mechanics again? It's frustrating both me and my allies by a huge amount. Any tips would be_** EXTREMELY**_ appeciated.